Tubular unit for water walls or the like



Patented Dec. 20, 1938 UNITED STATES 2,140,739 H TUBULAR UNIT FOR. WATERWALLS OR THE LIKE Herbert Frank, Kassel-Wilhelmshohe. Germany, assignorto The Superheater Company, New

York, N. Y.

Application January 30, 1937; Serial No. 123,189 In Germany February 5,1936 4 Claims. (01. 122 -235) The present invention relates toimprovements in water walls for the combustion chambers of boilers orthe like.

It has been the practice heretofore to cool a furnace wall in a boilerby circulating boiler water through tubes arranged in a row on the innersurface of the wall. In some cases bifurcated tube units have beenemployed and the constituent tubes have been curved near their ends toextend through the wall, both the curved tube portions and thebifurcations which join them to single tube lengths that connect intothe boiler circulation system being located within or outside the wall.Where the bifurcations of the units are disposed so that the tubeportions passing through the wall lie parallel to each other in ahorizontal plane, the openings made through the wall are relativelybroad and consequently impair the strength of the wall.

In accordance with the present invention the bifurcation or breechespiece of a unit which joins the two tubes thereof that lie on the innersurface of the wall is turned into a plane which is substantially atright angles to the tube portions on the wall so that in each unit theportions of the two tubes which extend through the Wall are disposedabove each other in a vertical plane at right angles to the wallsurface. As a result, the openings formed in the wall for extending theunits therethrough are about as narrow as would be required for a singletube.

In the drawing Fig. l is an elevational view, partly broken away, of aportion of a furnace wall having cooling tubes arranged thereon inaccordance with the invention.

Fig. 2 is a sectional view on the line 2-2 in Fig. 1 and shows themanner in which the end portions of the tubes and the bifurcationsjoining the latter are arranged so that the portions of the tubesprojecting through the wall are disposed in a single vertical plane, and

Figs. 3 and 4 are views similar to Figs. 1 and 2, respectively, butshowing an arrangement in which only one end of a unit has been bent inaccordance with the invention.

Referring to the drawing, the numeral I ll designates a furnace wall onthe inner surface of which is arranged a plurality of bifurcated coolingunits II having portions near their ends projecting through the wall andcommunicating with inlet and outlet headers I'l, I8 connected into thecirculation system of the boiler. Each unit I I comprises a pair oftubes I 2, I3 extending vertically of the wall and joined at each end bya bifurcation or breeches piece I4 to each other and to single tubelengths I6 connected with the headers I1 and I8. The tubes I2 and I3 ofall the units are arranged'parallel to the wall surface and as shown aredisposed close togetherin a single row in a vertical plane parallel tothe wall surface. If desired, the units might be connected to'functionas a superheater.

In accordance with the invention the bifurcation. l4 at each end of aunit I I isbent at substantially a ri ht angleto the tubes I2 and I3thereof so that the curved tube portions l'iwhich extend through thewall are located one above the other in a vertical plane perpendicularto that of the inner surface of the wall. As a result of thisarrangement the apertures made in the wall to permit the units II to beconnected with the headers I'I, I8 are narrower than would be the caseif the tube portions projecting through the wall laid alongside of eachother instead of being in a vertical plane. Consequently the wall is notweakened to the extent that it would be if the two tubes laid alongsideeach other where they passed through the wall because, in accordancewith the invention, the openings in the wall are about as wide as asingle tube and are spaced transversely of the wall. This feature is ofparticular advantage in situations where, as shown in Fig. 2, the upperportion ofa boiler wall is supported on a beam 20 or the like extendingtransversely of the wall at a point near the upper end of the coolingunits I I inasmuch as the wall ligaments 2| between the apertures forsuperposed tube portions I5 of adjacent units II provide a means forsupporting the upper portion of the wall on the beam 20.

A further advantage is that a water wall consisting of bifurcated unitsmay be readily installed in existing boilers. Only narrow apertures needbe cut in the Wall to receive the superposed end portions of the tubesand the ligaments left between the apertures support the upper part ofthe wall while installing the bifurcated units.

Another advantage is that even in cases where the bifurcations orbreeches pieces I4 are not located within or outside the wall they areprotected against heating by radiation from the fire inasmuch as theyare located behind the tube lengths I2, I3 which they join to form aunit.

In the arrangement illustrated in Fig. 3 the upper ends of the units I Iproject through the wall Ill near the top thereof and accordingly onlythe bifurcation at the lower end of each unit is bent to dispose thetube portions I5 in a vertical plane.

What I claim is:

1. In combination with a wall of a furnace or the like; a cooling screentherefor comprising a plurality of fluid circulating tubes disposedalongside each other in a row parallel to the inner surface of the walland having portions near their ends projecting through said wall, saidtube portions at at least one end of the tubes of each pair of adjacenttubes being bent at an angle to the portions thereof which line saidwall and disposed in superposed relation in a vertical planeperpendicular to that of said wall surface so that the aperture formedin said wall for projecting said tube portions therethrough is of awidth corresponding approximately to the diameter of a tube.

2. In combination with a wall of a furnace or the like; a cooling screencomprising a plurality of bifurcated, tubular, fluid circulating unitsarranged in a row on the inner surface of said wall, each unitconsisting of a pair of tube lengths lying alongside each other in aplane parallel to said wall surface and having end portions extendingthrough said wall and joined by a breechespiece disposed in a verticalplane perpendicular to the surface plane of said wall for disposing saidend portions in superposed relation in said vertical plane, whereby theaperture formed in said wall for extending the tube portions of eachunit therethrough is of a width substantially corresponding to thediameter of a tube of the unit.

3. In combination with a wall of a furnace or the like; a cooling screencomprising a plurality of bifurcated, tubular fluid circulating unitseach comprising a pair of parallelly extending tubes disposed alongsideeach other in a plane parallel to the surface of said wall and joinedtogether at each end by breeches pieces and having the end portions ofeach tube adjacent said breeches pieces bent at an angle to the majorportion of said tube to extend through said wall and disposed insuperposed relation in a plane at right angles to a plane passingthrough the axes of said major portions of said tubes.

4. In combination with a substantially vertical wall of a furnace or thelike; a cooling screen therefor comprising a plurality of fluidcirculating tubes spaced at distances less than a tube diameter andarranged in a single row disposed in a plane parallel to the innersurface of said wall and having portions near their ends projectingthrough said Wall and connected to a header located exteriorly of saidfurnace, said tube portions at at least one end of the tubes of eachpair of adjacent tubes being bent at an angle to the portions thereofwhich line said wall and disposed in superposed relation in a verticalplane perpendicular to that of said wall surface so that the apertureformed in said wall for projecting said tube portions therethrough forconnection to said headers is of a width corresponding approximately tothe diameter of a tube.

HERBERT FRANK.

